Grissom and Catherine investigate the stabbing death of an 80-year-old woman who lived in a run-down house full of cats; Nick and Sara comb through the remains of a car bombing that was, apparently, a murder plot gone awry.
After the CSI team interview the husband and his father-in-law, the CSI team return to the lab. Song begins when Sara is analyzing fingerprints on the explosive remnants, and finds a positive match.